Former Army Special Forces Sgt. Billy Costello slowly descended on a patch reef off Looe Key on Monday.

He quickly dropped to the bottom and began securing small staghorn coral fragments to the seafloor, in hopes they will one day blossom into large branching corals.

Costello is not your typical coral farmer, but a wounded veteran proving people can still achieve their goals despite their disabilities or life-altering injuries. He lost one of his legs after road-side bomb exploded near him while stationed in Afghanistan in September 2011 and now dives with the use of a prosthetic.

Costello was among nearly two dozen wounded veterans and the family members of fallen veterans to dive on Mote Marine Laboratory's coral restoration site, as part a wounded veterans' challenge and research project. Mote has set aside an area at its coral restoration site as a special remembrance area for fallen servicemen and women.

This week, Mote is hosting the Combat Wounded Veteran Challenge, SCUBAnauts and Gold Star Teen Adventures. Members of the groups are working with Mote scientists transplanting corals from its nursery to its restoration site.

More than seven years ago, Mote established an underwater coral nursery where scientists grow colonies of the threatened staghorn coral for replanting on decimated or damaged sections of reef within the Florida Keys National Marine Sanctuary. When the colonies reach a suitable size, small fragments nearly 2 inches long are snipped off and used to create a new colony -- similar to the way new plants are grown from cuttings of existing plants. Mote has about 15,000 coral colonies -- some 250,000 fragments -- growing in its nursery.

This is the third year SCUBAnauts International and the Combat Wounded Veteran Challenge have been with working in the nursery, coming out to help propagate coral and replant fragments in the transplant area near Looe Key

"I think they remind us that no matter what you keep going on, whether you lost or limb or suffered another injury," said SCUBAnauts member Mia Foisy, 14 of Dunedin, Fla.

Community service and the challenge is only part of the reason they are diving off the Florida Keys. Costello and other members of Combat Wounded Veteran Challenge are testing out various prosthetics and conducting other studies.

On this trip, Costello was hoping to use a new prosthetic that he designed, but it was not ready prior to the trip to the Keys, he said. Combat Wounded Veteran Challenge is working St. Petersburg College on designing and testing new prosthetics.

"I wanted to be part of a group that just doesn't put on events and challenges," Costello said. "I want to help build better prosthetics for the next generation."

Costello wants to design one that can be used for more than one purpose. Many prosthetics are designed for single uses and have to be taken on and off depending on what sports a person is engaged in.

"I want for a kid to come to Key West and not have to take a bunch prosthetics," Costello said. "I want him to be able to run down to the beach and just jump in with the other kids. I want versatility."

"I want to give back to science," Quintanilla said. "I want to help develop this technology."

Costello, Quintanilla and others will be working with prosthetist Michael McCauley in the pool at the military's dive school in Key West this week to "calculate their energy efficiency," McCauley said. McCauley plans to place six video cameras in the pool to record their swimming with and without the prosthetics. Also, he will be recording their blood pressure and heart rates.

"They are energy efficient, but not as much as they could be," McCauley said. "We are building a baseline and figuring out what we need to do," McCauley said.